Early 318 blocks

The only 318 blocks that will take that .090 cut and not flinch are the 66-down Polys.
They are still pretty cheap and plentiful, and STRONG. High nickle castings that weigh a good 30 pounds more than the later LA blocks.

Somebody better let Hensley Motorsports know that, because they've been building 4" plus bore LA 318s for twenty years or more.